Global hotspots for soil nature conservation.

Soils are the foundation of all terrestrial ecosystems1. However, unlike for plants and animals, a global assessment of hotspots for soil nature conservation is still lacking2. This hampers our ability to establish nature conservation priorities for the multiple dimensions that support the soil system: from soil biodiversity to ecosystem services. Here, to identify global hotspots for soil nature conservation, we performed a global field survey that includes observations of biodiversity (archaea, bacteria, fungi, protists and invertebrates) and functions (critical for six ecosystem services) in 615 composite samples of topsoil from a standardized survey in all continents. We found that each of the different ecological dimensions of soils-that is, species richness (alpha diversity, measured as amplicon sequence variants), community dissimilarity and ecosystem services-peaked in contrasting regions of the planet, and were associated with different environmental factors. Temperate ecosystems showed the highest species richness, whereas community dissimilarity peaked in the tropics, and colder high-latitudinal ecosystems were identified as hotspots of ecosystem services. These findings highlight the complexities that are involved in simultaneously protecting multiple ecological dimensions of soil. We further show that most of these hotspots are not adequately covered by protected areas (more than 70%), and are vulnerable in the context of several scenarios of global change. Our global estimation of priorities for soil nature conservation highlights the importance of accounting for the multidimensionality of soil biodiversity and ecosystem services to conserve soils for future generations.

Emodepside for Trichuris trichiura and Hookworm Infection.

BACKGROUND: Current treatments for soil-transmitted helminth infections in humans have low efficacy against Trichuris trichiura. Emodepside - a drug in veterinary use and under development for the treatment of onchocerciasis in humans - is a leading therapeutic candidate for soil-transmitted helminth infection. METHODS: We conducted two phase 2a, dose-ranging, randomized, controlled trials to evaluate the efficacy and safety of emodepside against T. trichiura and hookworm infections. We randomly assigned, in equal numbers, adults 18 to 45 years of age in whom T. trichiura or hookworm eggs had been detected in stool samples to receive emodepside, at a single oral dose of 5, 10, 15, 20, 25, or 30 mg; albendazole, at a single oral dose of 400 mg; or placebo. The primary outcome was the percentage of participants who were cured of T. trichiura or hookworm infection (the cure rate) with emodepside 14 to 21 days after treatment, determined with the use of the Kato-Katz thick-smear technique. Safety was assessed 3, 24, and 48 hours after the receipt of treatment or placebo. RESULTS: A total of 266 persons were enrolled in the T. trichiura trial and 176 in the hookworm trial. The predicted cure rate against T. trichiura in the 5-mg emodepside group (85% [95% confidence interval {CI}, 69 to 93]; 25 of 30 participants) was higher than the predicted cure rate in the placebo group (10% [95% CI, 3 to 26]; 3 of 31 participants) and the observed cure rate in the albendazole group (17% [95% CI, 6 to 35]; 5 of 30 participants). A dose-dependent relationship was shown in participants with hookworm: the observed cure rate was 32% (95% CI, 13 to 57; 6 of 19 participants) in the 5-mg emodepside group and 95% (95% CI, 74 to 99.9; 18 of 19 participants) in the 30-mg emodepside group; the observed cure rates were 14% (95% CI, 3 to 36; 3 of 21 participants) in the placebo group and 70% (95% CI, 46 to 88; 14 of 20 participants) in the albendazole group. In the emodepside groups, headache, blurred vision, and dizziness were the most commonly reported adverse events 3 and 24 hours after treatment; the incidence of events generally increased in a dose-dependent fashion. Most adverse events were mild in severity and were self-limited; there were few moderate and no serious adverse events. CONCLUSIONS: Emodepside showed activity against T. trichiura and hookworm infections. (Funded by the European Research Council; ClinicalTrials.gov number, NCT05017194.).

Beyond schistosomiasis: unraveling co-infections and altered immunity.

Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.

Soil nematode abundance and functional group composition at a global scale.

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

A Comparison of Markov and Mechanistic Models for Soil-Transmitted Helminth Prevalence Projections in the Context of Survey Design.

Globally, there are over 1 billion people infected with soil-transmitted helminths (STHs), mostly living in marginalized settings with inadequate sanitation in sub-Saharan Africa and Southeast Asia. The World Health Organization recommends an integrated approach to STH morbidity control through improved access to sanitation and hygiene education and the delivery of preventive chemotherapy (PC) to school-age children delivered through schools. Progress of STH control programs is currently estimated using a baseline (pre-PC) school-based prevalence survey and then monitored using periodical school-based prevalence surveys, known as Impact Assessment Surveys (IAS). We investigated whether integrating geostatistical methods with a Markov model or a mechanistic transmission model for projecting prevalence forward in time from baseline can improve IAS design strategies. To do this, we applied these 2 methods to prevalence data collected in Kenya, before evaluating and comparing their performance in accurately informing optimal survey design for a range of IAS sampling designs. We found that, although both approaches performed well, the mechanistic method more accurately projected prevalence over time and provided more accurate information for guiding survey design. Both methods performed less well in areas with persistent STH hotspots where prevalence did not decrease despite multiple rounds of PC. Our findings show that these methods can be useful tools for more efficient and accurate targeting of PC. The general framework built in this paper can also be used for projecting prevalence and informing survey design for other neglected tropical diseases.

Deworming and micronutrient status by community open defecation prevalence: An observational study using nationally representative data from India, 2016-2018.

BACKGROUND: Micronutrient deficiencies are widespread in India. Soil-transmitted helminth (STH) infections are acquired by interaction with soil and water contaminated by human feces and lead to blood loss and poor micronutrient absorption. The current recommendation for control of STH-related morbidity is targeted deworming, yet little is known about the effectiveness of deworming on micronutrient status in varying sanitation contexts. Ranging between 1% and 40% prevalence across Indian states, open defecation (OD) remains high despite India's investments at elimination by promoting community-wide sanitation. This variation provides an opportunity to study the relationship between deworming, micronutrient status, and OD at-scale. METHODS AND FINDINGS: Cross-sectional datasets that were representative for India were obtained the Comprehensive National Nutrition Survey in 2016 to 2018 (n = 105,060 individuals aged 1 to 19 years). Consumption of deworming medication was described by age and community OD level. Logistic regression models were used to examine the relationship between deworming, cluster OD, and their interactions, with anemia and micronutrient deficiencies (iron, zinc, vitamin A, folate, and vitamin B12), controlling for age, sex, wealth, diet, and seasonality. These regression models further allowed us to identify a minimum OD rate after which deworming becomes ineffective. In sensitivity analyses, the association between deworming and deficiencies were tested in subsamples of communities classified into 3 OD levels based on statistical tertiles: OD free (0% of households in the community practicing OD), moderate OD (>0% and <30%), or high OD (at least 30%). Average deworming coverage and OD prevalence in the sample were 43.4% [IQR 26.0, 59.0] and 19.1% [IQR 0, 28.5], respectively. Controlling for other determinants of nutritional status, adolescents living in communities with higher OD levels had lower coverage of deworming and higher prevalence of anemia, zinc, vitamin A, and B12 deficiencies. Compared to those who were not dewormed, dewormed children and adolescents had lower odds of anemia (adjusted odds ratio 0.72, (95% CI [0.67, 0.78], p < 0.001) and deficiencies of iron 0.78, (95% CI [0.74, 0.82], p < 0.001) and folate 0.69, (95% CI [0.64,0.74], p<0.001)) in OD free communities. These protective effects remained significant for anemia but diminished for other micronutrient deficiencies in communities with moderate or high OD. Analysis of community OD indicated a threshold range of 30% to 60%, above which targeted deworming was no longer significantly associated with lower anemia, iron, and folate deficiency. The primary limitations of the study included potential for omitted variables bias and inability to capture longitudinal effects. CONCLUSIONS: Moderate to high rates of OD significantly modify the association between deworming and micronutrient status in India. Public health policy could involve sequencing interventions, with focus on improving deworming coverage in communities that have achieved minimum thresholds of OD and re- triggering sanitation interventions in high OD communities prior to deworming days, ensuring high coverage for both. The efficacy of micronutrient supplementation as a complementary strategy to improve nutritional outcomes alongside deworming and OD elimination in this age group needs further study.

Green iron oxide nanoparticles and magnetic nanobiochar: enhancing tomato performance, phytochemicals, and root-knot nematode resistance.

BACKGROUND: Green nanoparticles are considered to be an effective strategy for improving phytochemicals and raising productivity in soil infected by root-knot nematodes. This work aims to understand the characteristics of certain nanomaterials, including non-iron (nFe), green non-iron (GnFe), and green magnetic nanobiochar (GMnB), and the effect of adding them at 3 and 6 mg kg- 1 on phytochemicals and tomato (Solanum lycopersicum) plant growth in soils infected by root-knot nematodes. RESULTS: Spectroscopic characterization of nanomaterials showed that nFe, GnFe, and GMnB contained functional groups (e.g., Fe-O, S-H, C-H, OH, and C = C) and possessed a large surface area. Application of GMB at 6 mg kg- 1 was the most efficient treatment for increasing the phytochemicals of the tomato plant, with a rise of 123.2% in total phenolic, 194.7% in total flavonoids, 89.7% in total carbohydrate, 185.2% in total free amino acids, and 165.1% in total tannin compared to the untreated soil. Tomato plant growth and attributes increased with increasing levels of soil nano-amendment in this investigation. The addition of GnFe3 and GnFe6 increased the reduction of root galls of root-knot nematodes by 22.44% and 17.76% compared with nFe3 and nFe6, respectively. The inclusion of the examined soil nano-amendments increased phytochemicals and reduced the total number of root-knot nematodes on tomato plants at varying rates, which played a significant role in enhancing tomato growth. CONCLUSIONS: In conclusion, treating tomato plants with GnFe or GMnB can be used as a promising green nanomaterial to eliminate root-knot nematodes and increase tomato yield in sandy clay loam soil.

Geospatial analysis and prevalence of Schistosoma mansoni and soil-transmitted helminth infections in an endemic area in Eastern Brazilian Amazon.

OBJECTIVES: This study evaluated the occurrence of Schistosoma mansoni and soil-transmitted helminths in an endemic area in the Eastern Brazilian Amazon, analysing prevalence and spatial distribution. METHODS: The study was conducted in four localities of Primavera Municipality, in Pará state. Data was obtained from the Decit 40/2012 project and the participants were divided into five age range categories for evaluation: children, adolescents, young adults, adults and elderly individuals. For the diagnostic tests, Kato-Katz slides were prepared to detect S. mansoni and soil-transmitted helminths eggs. The spatial distribution map and the Kernel Density Estimation were performed to assess the presence and location of infections. RESULTS: Stool samples revealed the presence of hookworms, S. mansoni, Ascaris lumbricoides and Trichuris trichiura eggs. Mono-, bi- and poly-parasitic infections were observed, with a significant prevalence of hookworm monoparasitism. CONCLUSIONS: The high frequency of children infected with soil-transmitted helminths confirms their significance as an ongoing public health problem in the poorest municipalities of Brazil. The Geographic Information System plays a crucial role in environmental surveillance and in the control of epidemics and endemic diseases, enabling accurate assessment and informed decision-making for their control.

Zinc status or supplementation and its relation to soil-transmitted helminthiasis in children: A systematic review.

Soil-transmitted helminths (STHs) parasitic infection is known as one of the most common infections around the world affecting more than a quarter of the world's population. The relationship between STH infections and micronutrient deficiencies are closely related and often coexist among the affected population. The study, therefore, aimed to summarise the available literature focusing on the effect of zinc status/deficiency or supplementation on STH infection or reinfection in children. For this purpose, we adopted a systematic approach and searched the existing literature on PubMed, Scopus, and Cochrane Library databases. A search term was entered to retrieve the available data. A total of 12 articles were included in this review after applying the inclusion/exclusion criteria. Most of the included studies reported a lower zinc status in children affected with any parasitic infection. Regarding the effect of zinc status and supplementation on parasitic infection in children, we found only a few studies (n = 4) with inconsistent result findings. This review reported that children infected with STH have lower zinc levels; however, a limited number of studies showed the effect of zinc supplements on the risk of STH warrants the need for further studies in this regard.

Living in the cracks: Two novel genera of Variosea (Amoebozoa) discovered on an urban sidewalk.

Biological soil crusts represent a rich habitat for diverse and complex eukaryotic microbial communities. A unique but extremely common habitat is the urban sidewalk and its cracks that collect detritus. While these habitats are ubiquitous across the globe, little to no work has been conducted to characterize protists found there. Amoeboid protists are major predators of bacteria and other microbial eukaryotes in these microhabitats and therefore play a substantial ecological role. From sidewalk crack soil crusts, we have isolated three naked amoebae with finely tapered subpseudopodia, and a simple life cycle consisting of a trophic amoeba and a cyst stage. Using a holistic approach including light, electron, and fluorescence microscopy as well as phylogenetics using the ribosomal small subunit rRNA gene and phylogenomics using 230 nuclear genes, we find that these amoeboid organisms fail to match any previously described eukaryote genus. However, we determined the amoebae belong to the amoebozoan lineage Variosea based on phylogenetics. The molecular analyses place our isolates in two novel genera forming a grade at the base of the variosean group Protosteliida. These three novel varioseans among two novel genera and species are herein named "Kanabo kenzan" and "Parakanabo toge."

Soil-transmitted helminths and associated factors among pregnant women in Doreni district, Oromia region, Ethiopia: a cross-sectional study.

BACKGROUND: Soil-transmitted helminthiasis (STH) refers to a set of parasitic illnesses caused by nematode worms and spread to people through faeces-contaminated soil. It is highly prevalent in low- and middle-income countries due to a lack of environmental sanitation and personal hygiene. Pregnant women are among the risk groups for infection by soil-transmitted helminths. Former studies of the disease burden among pregnant women in Ethiopia didn't indicate the intensity of parasitic infection. The aim of this study was to assess the prevalence and associated factors of soil-transmitted helminths among pregnant women. METHODS: An institution-based cross-sectional study was conducted among 416 randomly selected pregnant women. The data were collected using a structured interview-administered questionnaire and a laboratory test. The Kato-Katz technique was used to diagnose soil-transmitted helminthiasis and determine the intensity of the infection. The collected data were entered into Epi-Data version 4.6 and exported to SPSS version 25 for analysis. Multivariate logistic regression analysis was used to identify independent predictors of soil-transmitted helminths at a p-value < 0.05. RESULTS: The overall prevalence of soil-transmitted helminths among pregnant women was 30%. (95%, CI: 26-34%). Living in a rural area (AOR = 3.35; 95% CI = 1.83-6.13), drinking from an unprotected water source (AOR = 2.52; 95% CI = 1.45-4.37), not washing one's hand after the toilet (AOR = 2.75; 95% CI = 1.55-4.88), lacking health information (AOR = 1.70; 95% CI = 1.01-2.85), working as a daily labourer (AOR = 2.88; 95% CI = 1.01-8.20), and walking barefoot (AOR = 4.00; 95% CI = 2.29-7.00) were significantly associated with the presence of soil-transmitted helminths among pregnant women. CONCLUSION: The prevalence of STH was significantly moderate in the study area, where pregnant women were mostly affected by ascariasis and hookworms. Living in a rural area, being a daily labourer, walking barefoot, not washing hands after the toilet, drinking from an unprotected water source, and lacking health information were the determining factors. Interventions including health education, the expansion of pure drinking water sources, the promotion of personal hygiene, and the wearing of shoes are recommended to reduce the burden of soil-transmitted helminths in the study area.

Altered Offspring Immunity in Maternal Parasitic Infections.

Maternal infection during pregnancy is known to alter the development and function of offspring's immune system, leading to inappropriate immune responses to common childhood infections and immunizations. Although this is an expanding field, maternal parasitic infections remain understudied. Millions of women of reproductive age are currently at risk for parasitic infection, whereas many pregnant, chronically infected women are excluded from mass drug administration due partially to a lack of resources, as well as fear of unknown adverse fetal developmental outcomes. In areas endemic for multiple parasitic infections, such as sub-Saharan Africa, there are increased rates of morbidity and mortality for various infections during early childhood in comparison with nonendemic areas. Despite evidence supporting similar immunomodulatory effects between various parasite species, there is no clear mechanistic understanding of how maternal infection reprograms offspring immunity. This brief review will compare the effects of selected maternal parasitic infections on offspring immunity.

Control of the plant-parasitic nematode Meloidogyne incognita in soil and on tomato roots by Clonostachys rosea.

AIMS: Clonostachys rosea is a well-known mycoparasite that has recently been investigated as a bio-based alternative to chemical nematicides for the control of plant-parasitic nematodes. In the search for a promising biocontrol agent, the ability of the C. rosea strain PHP1701 to control the southern root-knot nematode Meloidogyne incognita was tested. METHODS AND RESULTS: Control of M. incognita in vitro and in soil by C. rosea strain PHP1701 was significant and concentration dependent. Small pot greenhouse trials confirmed a significant reduction in tomato root galling compared to the untreated control. In a large greenhouse trial, the control effect was confirmed in early and mid-season. Tomato yield was higher when the strain PHP1701 was applied compared to the untreated M. incognita-infected control. However, the yield of non-M. incognita-infected tomato plants was not reached. A similar reduction in root galling was also observed in a field trial. CONCLUSIONS: The results highlight the potential of this fungal strain as a promising biocontrol agent for root-knot nematode control in greenhouses, especially as part of an integrated pest management approach. We recommend the use of C. rosea strain PHP1701 for short-season crops and/or to reduce M. incognita populations on fallow land before planting the next crop.

Factors associated with hookworm and Schistosoma mansoni infections among school-aged children in Mayuge district, Uganda.

BACKGROUND: Hookworm infection and schistosomiasis are two of sub-Saharan Africa's most common neglected tropical diseases. An annual mass drug administration (MDA) program against schistosomiasis and soil-transmitted helminths (STHs), including hookworm, has been implemented in Mayuge district, Uganda, since 2003 to date. However, hookworm and schistosomiasis remain prevalent in Mayuge district. Understanding the factors that predispose children to these infections in the context of MDA could inform interventions to reduce prevalence in Uganda and similar settings. METHOD: This cross-sectional study took place in 33 randomly selected primary schools in the Mayuge district from January to February 2022. Children in primary classes 4 or 5, in the selected schools provided single stool samples and completed questionnaires. Stool specimens were examined using the Kato-Katz method to determine the prevalence of hookworm and schistosomiasis. We performed univariable and multivariable logistic regression to assess the associations of each infection with potential risk factors. RESULT: A total of 1,617 students (mean age 12.1 years, 50.1% male) were enrolled. The prevalence of hookworm infection and schistosomiasis was 21.8% (95% confidence interval (CI): 19.8-23.9%) and 18.7% (95% CI: 16.8-20.7%), respectively. In multivariable analysis, longer water fetching time (over 30 min versus less than 30 min) and working daily in the soil were associated with increased odds of hookworm infection (adjusted odds ratio (AOR): 1.49, 95% CI: 1.13-1.96 and 1.37, 95% CI: 1.03-1.82, respectively). Higher odds of schistosomiasis were linked to proximity to water bodies within a one-hour walking distance (AOR: 1.84, 95% CI: 1.35-2.50), and not always washing hands before eating (AOR: 2.00, 95% CI: 1.50-2.67). Swimming, bathing, or washing in water bodies twice a week, compared to never, also increased schistosomiasis odds (AOR: 2.91, 95% CI: 1.66-5.13). CONCLUSION: Consistent with the mechanisms of acquisition, hookworm infection increased with exposure to soil, and schistosomiasis increased with exposure to unclean water. Our findings highlight the importance of Water, Sanitation, and Hygiene programs and strategies aimed at reducing exposure within the framework of Neglected Tropical Disease elimination programs.

Mass drug administration campaigns: comparing two approaches for schistosomiasis and soil-transmitted helminths prevention and control in selected Southern Malawi districts.

BACKGROUND: Mass drug administration is one of the key interventions recommended by WHO to control certain NTDs. With most support from donors, health workers distribute antihelminthic drugs annually in Malawi. Mean community coverage of MDA from 2018 to 2020 was high at 87% for praziquantel and 82% for albendazole. However, once donor support diminishes sustaining these levels will be challenging. This study intended to compare the use of the community-directed intervention approach with the standard practice of using health workers in delivery of MDA campaigns. METHODS: This was a controlled implementation study carried out in three districts, where four health centres and 16 villages in each district were selected and randomly assigned to intervention and control arms which implemented MDA campaigns using the CDI approach and the standard practice, respectively. Cross-sectional and mixed methods approach to data collection was used focusing on quantitative data for coverage and knowledge levels and qualitative data to assess perceptions of health providers and beneficiaries at baseline and follow-up assessments. Quantitative and qualitative data were analyzed using IBM SPSS software version 26 and NVivo 12 for Windows, respectively. RESULTS: At follow-up, knowledge levels increased, majority of the respondents were more knowledgeable about what schistosomiasis was (41%-44%), its causes (41%-44%) and what STH were (48%-64%), while knowledge on intermediate host for schistosomiasis (19%-22%), its types (9%-13%) and what causes STH (15%-16%) were less known both in intervention and control arm communities. High coverage rates for praziquantel were registered in intervention (83%-89%) and control (86%-89%) communities, intervention (59%-79) and control (53%-86%) schools. Costs for implementation of the study indicated that the intervention arm used more resources than the control arm. Health workers and community members perceived the use of the CDI approach as a good initiative and more favorable over the standard practice. CONCLUSIONS: The use of the CDI in delivery of MDA campaigns against schistosomiasis and STH appears feasible, retains high coverages and is acceptable in intervention communities. Despite the initial high costs incurred, embedding into community delivery platforms could be considered as a possible way forward addressing the sustainability concern when current donor support wanes. TRIAL REGISTRATION: Pan-African Clinical Trials Registry PACTR202102477794401, date: 25/02/2021.

Joint Impacts of Meloidogyne incognita and Soil Nutrition on Solanum lycopersicum var. cerasiforme.

Strategies for plant nutrient resource allocation under Meloidogyne spp. infection and different soil nutrient conditions are not well established. In response, the objectives of this research are to determine if increased vegetative growth of Solanum lycopersicon var. cerasiforme (cherry tomato) under high nutrition enhances resistance to M. incognita and whether adaptive strategies for growth, reproduction, and nutrient uptake by cherry tomato infected with M. incognita alter nutrient availability. The study was conducted under greenhouse conditions using high, medium, and low soil nutrient regimes. The research results indicate that the total biomass of cherry tomato was less in the presence of M. incognita infection under all three nutrient conditions, compared with plants grown in the absence of this nematode. However, the increase in the root/shoot ratio indicates that cherry tomato allocated more resources to belowground organs. Under the combined impacts of M. incognita infection and low or medium soil nutrition, the nitrogen content in root system tissues and the phosphorus content in shoot system tissues were increased to meet the nutrient requirements of galled root tissue and plant fruit production. It is suggested that plants increase the allocation of reproductive resources to fruits by improving phosphorus transportation to the aboveground reproductive tissues under low and medium nutrient conditions. Overall, the study highlights a significant impact of soil nutrient levels on the growth and resource allocation associated with M. incognita-infected cherry tomato. In response, soil nutrient management is another practice for reducing the impacts of plant-parasitic nematodes on crop production.

Cross-Sectional Study of Soil-Transmitted Helminthiases in Black Belt Region of Alabama, USA.

We conducted a cross-sectional study to determine the prevalence of soil-transmitted helminthiases (STH) in areas of rural Alabama, USA, that have sanitation deficits. We enrolled 777 children; 704 submitted stool specimens and 227 a dried blood spot sample. We microscopically examined stool specimens from all 704 children by using Mini-FLOTAC for helminth eggs. We tested a subset by using molecular techniques: real-time PCR analysis for 5 STH species, TaqMan Array Cards for enteric helminths, and digital PCR for Necator americanus hookworm. We analyzed dried blood spots for Strongyloides stercoralis and Toxocara spp. roundworms by using serologic testing. Despite 12% of our cohort reporting living in homes that directly discharge untreated domestic wastewater, stool testing for STH was negative; however, 5% of dried blood spots were positive for Toxocara spp. roundworms. Survey data suggests substantial numbers of children in this region may be exposed to raw sewage, which is itself a major public health concern.

Surveillance for Soil-Transmitted Helminths in High-Risk County, Mississippi, USA.

Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless, further surveillance in other high-risk Mississippi counties is warranted.

Soil Protists Can Actively Redistribute Beneficial Bacteria along Medicago truncatula Roots.

The rhizosphere is the region of soil directly influenced by plant roots. The microbial community in the rhizosphere includes fungi, protists, and bacteria: all play significant roles in plant health. The beneficial bacterium Sinorhizobium meliloti infects growing root hairs on nitrogen-starved leguminous plants. Infection leads to the formation of a root nodule, where S. meliloti converts atmospheric nitrogen to ammonia, a bioavailable form. In soil, S. meliloti is often found in biofilms and travels slowly along the roots, leaving developing root hairs at the growing root tips uninfected. Soil protists are an important component of the rhizosphere system, able to travel quickly along roots and water films, who prey on soil bacteria and have been known to egest undigested phagosomes. We show that a soil protist, Colpoda sp., can transport S. meliloti down Medicago truncatula roots. Using model soil microcosms, we directly observed fluorescently labeled S. meliloti along M. truncatula roots and tracked the displacement of the fluorescence signal over time. Two weeks after co-inoculation, this signal extended 52 mm farther down plant roots when Colpoda sp. was also present versus treatments that contained bacteria but not protists. Direct counts also showed protists are required for viable bacteria to reach the deeper sections of our microcosms. Facilitating bacterial transport may be an important mechanism whereby soil protists promote plant health. IMPORTANCE Soil protists are an important part of the microbial community in the rhizosphere. Plants grown with protists fare better than plants grown without protists. Mechanisms through which protists support plant health include nutrient cycling, alteration of the bacterial community through selective feeding, and consumption of plant pathogens. Here, we provide data in support of an additional mechanism: protists act as transport vehicles for bacteria in soil. We show that protist-facilitated transport can deliver plant-beneficial bacteria to the growing tips of roots that may otherwise be sparsely inhabited with bacteria originating from a seed-associated inoculum. By co-inoculating Medicago truncatula roots with both S. meliloti, a nitrogen-fixing legume symbiont, and Colpoda sp., a ciliated protist, we show substantial and statistically significant transport with depth and breadth of bacteria-associated fluorescence as well as transport of viable bacteria. Co-inoculation with shelf-stable encysted soil protists may be employed as a sustainable agriculture biotechnology to better distribute beneficial bacteria and enhance the performance of inoculants.

Prevalence of Schistosoma mansoni, soil-transmitted helminths and intestinal protozoa in orphans and street children in Mwanza city, Northern Tanzania.

BACKGROUND: Parasitic infections are highly prevalent in low-income environments worldwide. While orphans and street children represent a particularly vulnerable population group, they are often exempt from preventive interventions such as Mass Drug Administration. In part, this could be due to a lack of data showing the burden of disease in this group. This study aims to address this gap. METHODS: For this cross-sectional study, 144 orphans and 112 street children were screened for Schistosoma mansoni (S. mansoni), Schistosoma haematobium (S. haematobium), soil-transmitted helminths and intestinal protozoa using POC-CCA testing, urine filtration, and Kato-Katz technique. Nutritional status, water- and washing patterns were determined using a standardised questionnaire. Ultrasonography was performed to screen for organ abnormalities. RESULTS: The prevalence of S. mansoni determined by POC-CCA-test was 65.9% for orphans and 94.5% for street children. 19.2% of the orphans tested positive for S. mansoni in Kato Katz. Of the street children, 77.1% showed positive test results in Kato-Katz. Only 1.3% of the orphans stated in the questionnaire that they use the lake to wash, whereas 91.1% of the street children named the lake as at least one of their options for washing. Microscopy showed positive results for Giardia intestinalis (G. intestinalis) in 8.2% and for Entamoeba histolytica/dispar (E. histolytica/dispar) in 23% of orphans and 8.1% for G. intestinalis, and 23.8% for E. histolytica/dispar in street children. In the ultrasonography, we did not observe patterns that indicate severe periportal fibrosis. CONCLUSION: The results indicate a significantly higher rate of infections with S. mansoni in street children compared with orphans. This might be explained by the lack of access to adequate sanitation for street children as well as regular contact with the water of Lake Victoria. However, we did not find similar results concerning infection rates with protozoa. The study results show overall inadequate living conditions in this study population, which could be addressed by public health interventions.